Method and apparatus for drawing glass in cylindrical form



Sept. 15, 1931. as. HOWARD METHOD AND APPARATUS FOR DRAWING GLASS IN CYLINDRICAL FORM In 0912 tor @e K-i nrm? Original Filed May 28, 1923 Attqrn gy- Wl'tness; A

Patented Sept. 15, 1931 orrEo STATES PATENT OFFICE GEORGE E. HOWARD, OF BUTLER, PENNSYLVANIA, ASSIGNOR TO HARTFORD-EMPIRE COMPANY, A CORPORATION OF DELAWARE METHOD AND APPARATUS FOR DRAWING GLASS IN CYLINDR-IGAL FORM Original application filed May 28, 1923, Serial No. 642,021. Divided and this application filed February 8, 1927. Serial No. 168,774.

This application is a division of my 00- pending application filed May 28, 1923, Serial N 0. 642,021 and is filed for the purpose of claiming the system illustrated in Figure 6 of the drawing of the original application identified above, wherein molten glass is shaped continuously into cylindrical form by flowing a stream of molten glass upon the inner surface of a rotating conical receiver or funnel with which a mandrel is arranged to cooperate.

The single figure of the accompanying drawing is an enlarged reproduction of F igure 6 of the original application and is a vertical sectional view taken on the axis of rotation of the funnel or receiver.

In the drawing the numeral 120 indicates a receptacle for molten glass provided with a downwardly directed discharge outlet 121 which, as shown, is not obstructed by a plug or other implement, although such an implement may be provided, if desired, for shutting off the flow of glass at this point or for obtaining direct regulation of the glass flow at the outlet. Means are preferably provided for maintaining the glass in the container 120 at a constant level and at a constant temperature. Such arrangements are common in the glass-feeding art and are therefore not illustrated herein.

Aestream of glass 122 issues continuously from the outlet 121 and is received upon the inner surface of a rotating funnel or receiver 123 having a refractory lining 124. The receiver 123 is shown provided with a spur gear 125 which may be driven by any suit able power connections, not shown. The

glass is deposited evenly upon the funnel, as

shown at- 126, and descends in an'annular stream when tubing is being manufactured.

This stream may accumulate somewhat just above a hollow former 128.

A mandrel 129 is shown suspended within the receiver 123 to assist in cooling, smoothing and shaping the interior of the descending stream of glass. This mandrel also exerts a mixing action on the glass. and thus increases its homogeneity. As shown, the mandrel 129- is suspended from a cylindrical support 130 which extends through an opening. in a bracket 131 secured to the side of the glass receptacle 120. A screw 132 extends from the top of the supporting memher 130 and through an opening in an angle bracket 133. Nuts 134 and 135 are applied to the screw 132 above-and below the bracket 133 for adjusting the vertical position of the mandrel 129. A set screw 136 may be provided to secure the support 130 inits adjusted position and particularly against rotation.

Below/the former 128 is shown a set of ironing or compressing rollers 137 mounted in a stationary frame 139 and individually rotated at the same surface speed as that of the descending glass tube 140. The descent of the glass may beassisted by any suitable traction means, such for example as the drawing devices shown in my original apmechanism that may be used can be rotatedi bodily in order to avoid twisting the glass, or these parts maybe stationary, in which case a former, such as the former 128, may be relied upon to check the rotation of the g'lass and thereby to produce a cylinder which descends without rotating.

Vhcn making tubing, blowing air may be supplied to the interior of the glass tube 140 through the mandrel 129 in the manner shown in various figures of my original application, or in any suitable known mannerr The specific mechanism shown herein is characterized by the fact that the receiver or funnel rotates on a vertical axis, the glass being drawn vertically downward. This simplifies the arrangements for supplying the glass to the receiver and tends to insure a uniform product, as themove ment of the glass is mainly downward. Moreover, the vertically adjustable mandrel of my present system is maintained stationary during the drawing of glass from the rotating receiver or may be rotated at a 1 tween said implement and the wall of an outlet at oneend of said'receiver. and forming the withdrawn glass into tubing.

2. The method of drawing glass tubing continuously, which comprises flowing a stream of molten glass upon the inner surface of a tapered receiver, rotating said receiver on a verticalaxis, withdrawing the glass downwardly through an opening at the lower and smaller end of said receiver, and applying a stationary implement to the :interior of the glass adjacent to the said ,lower opening of the receiver, and forming the glass so withdrawn into a form of uniform crox sect-ion to produce tubing.

-3. Apparatus for continuously drawing glass tubing, comprising a hollow receiver having a discharge outlet, means for rotating said receiver, means for flowing a stream of molten glass upon the inner surface of said receiver, a stationary mandrel extending into said receiver and adapted to engage the glass therein adjacent to said outlet, and means for forming the glass issuing from said outlet into tubing.

4. Apparatus, for continuously drawing glass in tubular form, comprising a hollow and downwardly tapering receiver-having a drawing opening at its lower end, means for flowing a continuous stream of molten glass upon the inner surface of said receiver, means for rotating said receiver and a stationary mandrel extending into said receiver and into said drawing opening and arranged to engage the glass adjacent to the lower end of said receiver, said mandrel and the wall of said opening cooperating to im-- part an annular form to the glass issuing from said drawing opening.

5. The method of drawing glass tubing or cane, which comprises discharging molten glass from an outlet of a receptacle in a rotating continuous stream, forming said stream into .substantially cylindrical form while the glass thereof is still plastic, and

compressin the stream so formed by applying to t e surface thereof rollers rotating about axes parallel to the axis of the stream at substantially the same surface speed as that of said stream.

6. Apparatus for drawing glass tubing or cane, comprising an upright receptacle having a drawing opening, means for rotating said receptacle about a vertical axis passing through the center of said drawing opening, means for supplying molten glass to said receptacle, an annular forming device located below said receptacle and substantially in axial alignment with the drawing opening of said receptacle for forming the glass issuing from said drawing opening into substantially cylindrical form and a plurality of pressing rolls located below said forming device in position to surround and to have rolling contact with the substantially cylindrical stream of glass below the forming device, said rolls being adapted to rotate about axes parallel with the longitudinal axis of said substantially cylindrical stream of glass.

7. Apparatus for drawing glass tubing, comprising a receptacle having its inner walls converging to a drawing opening, a normally stationary but longitudinally adjustable mandrel extending into said receptacle and through the drawing opening without closing -said drawing opening, means for rotating said receptacle about the axis of said drawing opening, means for supplying molten glass to said receptacle, whereby glass will issue in an annular stream through the space between said mandrel and the wall of said drawing opening, and an annular forming device located substantially in axial alignment with said drawing opening for forming said annular stream of glass into substantially cylindrical form.

8. Apparatus for drawing glass tubing,

comprising a receptacle having its inner walls 'co'nvergingto a drawing opening, a normally stationary but longitudinally adjustable mandrel extending into said receptacle and through the drawing opening without closing said drawing opening, means for rotating said receptacle about the axis of said drawing opening, means for supplying molten glass to said receptacle, whereby glass will issue in an annular stream through the space between said mandrel and the wall of said drawing opening, and an annular forming device located substantially in axial ali nment with said drawing opening for orming said annular stream of glass into substantially cylindrical form, the projecting end of said mandrel extending into said forming device in spaced relation to-the inner wall of the latter.

Signed at Butler, Pennsylvania, this 5th day of January, 1927 GEORGE E. HOWARD. 

